Typically, roofs that are shingled are sloped roofs; for example, roofs having slopes with lower edges and upper edges. In starting to shingle a roof, before actual roofing shingles are applied, a course of starter strip shingles is applied, along the lower edge of the roof. In some instances, two courses of starter strip shingles are applied along the lower edge of the roof, one course over the other. Then, typically, a first course of roofing shingles is applied, overlying the uppermost course of starter strip shingles (or overlying the single course of starter strip shingles where only a single course of starter strip shingles is being used). In many instances, the roofing shingles that are being applied to the roof are shingles having upper headlap portions and lower tab portions, with the tab portions comprising spaced-apart tabs that are spaced by vertical slots. The slots can be of narrow width, or can be of greater width, such as the width of a tab of the roofing shingle.
Whatever the spacing of tabs of roofing shingles, or width of slots separating such tabs, it will be apparent that, whenever a course of roofing shingles having tabs that are spaced apart by slots of any width are placed into overlying relation over a course of starter strip shingles, portions of the upper or anterior surface of the course of starter strip shingles are visible through the open slots that separate adjacent tabs of roofing shingles in the course of roofing shingles placed thereover.
Thus, the use of starter strip shingles is necessary for the protection of the roof, as well as for aesthetic purposes.
It is also customary that starter strip shingles have sealant along their leading edges (lowermost edges) to allow the first course of roofing shingles to seal thereover.
In many instances, often depending upon the particular design of the roofing shingles that are to be applied, the starter strip shingles may need to be applied in double thickness, for example in two courses, one course applied over the other. For example, U.S. Pat. No. 6,199,338 discloses a double course of starter strip shingles.
When a double thickness (or two courses) of starter strip shingles are used, and then a first course of roofing shingles is applied thereover, with the shingles in the first course of roofing shingles being of greater width than the underlying starter strip shingles from top to bottom, as measured from the top edge of the roofing shingle to the bottom edge of the roofing shingle, the roofing shingle forms a substantial hump, where it transitions from the upper edge of the double layer of starter strip shingles to the roof deck where no starter strip shingles are applied. Such a transition hump may be not only aesthetically unsightly, but may also cause the first course of roofing shingles to crack or tear at the point of the transition, possibly creating a leak at the location of the transition just above the upper edges of the starter strip shingles.
In the roofing industry, such potential failure of a first course of roofing shingles is recognized as being a potential problem when a double course of starter strip shingles is used beneath a first course of roofing shingles. In order to minimize such prospects of roofing shingle failure, some manufacturers have made starter strip shingles of varying widths from upper to lower edges of the starter strip shingles, so that the transition of an overlying roofing shingle is more gentle, in that the roofing shingle undergoes a step down from a second applied course of starter strip shingles to a first course of starter strip shingles, and then further steps down to the roof deck. Such starter strip shingles of varying widths have, to date, been applied in roll form, generally from a roll that is about 36 inches in width, as measured from upper edge to lower edge, with such a roll being slit longitudinally, creating two rolls, of different widths, such as one roll being 22 inches in width from upper edge to lower edge that is first applied to a roof deck, with the second roll being, for example, 14 inches in width that is then applied to the roof deck, forming a second starter strip course over the first starter strip course, with a second starter strip course being 8 inches shorter in width.
Thus, the large hump created from transitioning a first course of roofing shingles from a double course of starter strip shingles that are of the same width, as shown in the prior art illustration of FIG. 1, is feathered or smoothed out somewhat in the prior art illustration of FIG. 2.